The socket S1 is an AMD®-built socket made to house central processing units (CPUs) for the mobile computing, or laptop, market. There are 638 contacts included on the socket S1, and it comes with a rotating locking unit instead of a lever device like most other sockets. As of July 2011, there are four CPUs made to work with this socket, though there are others that can fit into the S1 socket. In terms of power, the socket S1 can reach about 1.8 to 3.2 gigahertz (GHz), with most processors clocking in around 2.1 to 2.5 GHz; this socket also can support four cores at once. There were four total revisions of this socket before it was retired, with the last one adding new core and memory support.
When it comes to the main design of the socket S1, the contacts, this socket looks like many others. There are a total of 660 contacts, but 22 of them are plugged, so 638 are electronically active; in the center there is a small square without any contacts. The actuator, or locking unit, is different from other sockets. With most sockets, there is a lever that is pulled up to unlock the CPU; with the S1 socket, the actuator is half-turned to unlock the CPU.
There have been four processors officially created for the socket S1. These are the Athlon 64 X2®, Turion 64 MK®, Turion 64 X2® and Mobile Sempron®. All four of these processors are used in laptops rather than in desktop computers.
All sockets are made to support a certain range of power, which helps the CPU perform its duties. The socket S1 can reach up to 3.2 GHz and has a low range of 1.8 GHz. CPUs commonly hit the middle of this range, between 2.1 and 2.5 GHz. The data-transferring rates for memory range from around 800 to 1,333 megahertz (MHz).
In total, there have been four revisions of the socket S1, with the last one referred to as S1g4. This revision made improvements over the other ones by including extra core support, up to four separate cores for higher processing abilities. This socket also supports double data rate type three (DDR3) synchronous dynamic random access memory (SDRAM), which the earlier versions did not support. While the last revision has many new supports, it is physically identical to the other versions; all the differences are electronically present.